This CFM/CMM Thermo-Anemometer can simultaneously display of Air Flow or Air Velocity plus Ambient Temperature. Easy to set area dimensions (ft² or m²) are stored in the meter’s internal memory for the next power on. Additional features include: 20 point average for Air Flow and 3% velocity accuracy via low friction 2.83 in.D (72mm) ball bearing vane wheel on 3.9ft (120cm) cable.